1. Field of the Invention
The present invention relates to a breathing device for administering a liquid medicant to a patient. In particular, the present invention is directed to a breathing device that is simple in design, easy to manufacture, and is comprised of a relatively small number of components.
2. Prior Art
The use of nebulizers or atomizers with intermittent positive pressure breathing (IPPB) equipment, ventilators, or with the patient's own natural breathing effort is widely practiced. Nebulizers or atomizers are used to deliver liquid medicants for a wide variety of medical conditions.
There is increasing concern over treatment of contagious diseases, the concern being both for infection of other patients and for infection of medical personnel. For this reason, the use of disposable nebulizers which are discarded after a single patient's use has become popular. While many nebulizers are produced so that they may be washed and sterilized, and then reused, there is a demand for disposable nebulizers.
Although existing nebulizers may be discarded after each use, it is costly to discard the more expensive, complicated nebulizers.
Disposable nebulizers produced in the past have not been as effective as the reusable nebulizers. As an example, the Applicant's invention shown in U.S. Pat. No. 4,007,238 includes a feature not common to disposable nebulizers. The performance of the nebulizer is directly responsive to the patient's own breathing. Stated another way, the output of medication matches the patient's changing rate of inhalation. All of the air inhaled by the patient is directed past the saturated mist. As the air flow to the patient's lungs is increased, additional liquid particles are delivered to the lungs because these particles are surrounded by a shroud of high relative humidity. Conversely, when the air flow to the patient's lungs is decreased, the number of liquid particles is decreased. The amount of saturated air delivered to the patient is directly responsive to the increase or decrease in the patient's breathing.
Additionally, an extremely small average particle size is called for in delivery of liquid medication. For the liquid medication to reach the smaller passages in the bronchial tubes and lungs, the size of the liquid particles must be below five microns. These small particles are below the visible range.
Furthermore, the actual particle count delivered is of great importance.
It is desirable to incorporate these features in a nebulizer which is simple in design and is directed to the disposable market.
Accordingly, it is a principal object and purpose of the present invention to provide a nebulizer which is simple in construction, which is easy to produce, and which may be fabricated from a minimum number of components.
It is an additional object and purpose of the present invention to provide a disposable nebulizer having a medication delivery system that is responsive to the patient's breathing.